"Tights and leggings are okay in my book, but pants are just so boring."

Just when we thought our bottle-blond pop stars couldn't get any weirder, a whiskey-fueled, glitter-encrusted 23-year-old named Ke$ha proved us so very wrong, unleashing her hard-partying manifesto "Tik Tok," in which she compares herself to P. Diddy and boasts about brushing her teeth with a "bottle of Jack." The daughter of country songwriter Pebe Sebert, Ke$ha wrote most of her debut album, Animal, while she was "broke as hell," living out of her car in Los Angeles and recording background vocals for artists like Flo Rida. "People give me grief about my lyrics," she says, "but I try to show the freedom to be yourself, unapologetically and irreverently." This summer, she'll take her wacky live show on the road—she's known for wearing headdresses and doing cartwheels onstage—opening for Rihanna. "If I don't perform so hard that I feel like I'm gonna throw up, I didn't do a good job," she insists, though as her music suggests, her shows aren't the overproduced spectacles of her blond counterparts. "I just have fun."—Julie Vadnal

"I love sweaters that feel secondhand. There's something about things with a past that I like."

Among the benefits of being Charlotte Gainsbourg—besides being a French national treasure, an indie film icon, and muse of Balenciaga designer Nicolas Ghesquière (with the innate ability to turn jeans and a T-shirt into the embodiment of "effortless cool")—is knowing that when you're ready to record, music's finest minds will line up to work with you. The 38-year-old's latest effort, IRM, is the result of a year-and-a-half-long collaboration with Beck—her breathy vocals the perfect match for his folky-electronic sound. Much has been made of the title, the French
acronym for MRI, an experience Gainsbourg became all too familiar with in 2007 after suffering a near-fatal brain hemorrhage due to a water-skiing accident. Though the machine's discordant sound pops up on the title track—"I liked the idea of putting something clinical into a song"—she insists that Beck wasn't directed to write about the ordeal. "Beck wrote a lyric, `Drill my brain/ All full of holes' [for the song `Master's Hands']," she says. "At the time, he didn't realize that I actually had a hole in my head!"—Maggie Bullock

"My look isn't plotted out, like, I'm going to have red hair because it's a new record. It has to be genuine, not a branding concept."

Piano-soul high priestess Alicia Keys has won 12 Grammys and sold more than 30 million records. But last fall, just before releasing her fourth studio album, The Element of Freedom, Keys also sang the hook on Jay-Z's "Empire State of Mind," nearly upstaging Mr. Carter and solidifying the single as New York City's definitive anthem of the aughts. "It was so potent from the very beginning," says the 29-year-old Manhattan native, who grew up in Hell's Kitchen and learned to play the piano by age seven. Keys insists she's always possessed "definite gut feelings about things," which should work to her advantage when she writes her musical ("I want to create the new Broadway") or records with her dream collaborators, Kings of Leon. "It's an instinct. And I don't take that for granted, especially with music." Like in 2001, when she chose "Fallin' " to be her first single even though Jay-Z suggested she go with "Girlfriend." "He reached out to me months later and was like, `Yeah, you were totally right.' "—J.V.

Photographed January 13, 2010 at Hudson Bar and Books in New York City

"When you make music with boys, they don't tell you you're pretty or you're playing very well. We'll say, `You're good. You look nice today.' "—Z Berg

"We're obsessed with the Beatles and the Who and the Kinks," says the Like's drummer, Tennessee Thomas. "They made playing music seem like the most fun thing ever." The same can be said for the Like, who play their '60s-girl-group-inspired songs with gritty, garage-rock energy while sporting cat eyeliner and updos. Their combo of sassy lyrics and inimitable throwback style has caught the eye of admirers such as Zac Posen, who cast them in the Gia Coppola–directed commercials for his Target line, and superproducer Mark Ronson, who helmed their sophomore effort, Release Me, on which the girls channel the brio of their '60s-era heroes and capture what lead singer Z Berg calls the "raw, honest sound of vintage records." The Los Angeles–based band has evolved since it was founded in 2001 by then-teenagers Berg and Thomas (the lineup is now completed by bassist Laena Geronimo and keyboardist Annie Monroe), touring alongside acts such as the Arctic Monkeys and Kings of Leon. "We were so young when we started," Berg admits. "We're now in a different league."—April Long

"I wanted to do something fashion-forward. I love hearing my music when models walk down the runway."

"It's great to walk in your flip-flops and sweatpants to work," the always meticulously attired Christina Aguilera says rather amusingly about making ­Bionic, her first new album in four years. A procession of songstresses, from Sia to M.I.A. and Goldfrapp to Santigold, flew in to collaborate with the extraordinary Xtina in the studio Ozzy Osbourne built at the Hollywood ­mansion you know from the reality show—now home to Aguilera, husband Jordan Bratman, and 2½-year-old son Max. The singer with the supersonic pipes, who shined from the get-go but didn't always seem to be enjoying herself, is feeling comfortable in her own skin. The ­result: a genre-jumping tour de force, from the club-ready "Not Myself Tonight" to the title track's hip-hop fun house of ­noise. But it's the emotionally raw ballads ­Aguilera wrote with Aussie up-and-comer Sia that Aguilera says anchor the record. "When you connect with someone," she says, "magic happens." With Aguilera all over the airwaves this summer, there will be magic—and much joy—in clubland.—Ben Dickinson

"The way I visually portray myself depends on my mood. This record, I'm going for a theatrical vibe."

It's been six years since Kelis' "Milkshake" brought all the boys to the yard, and four since we heard her last album, Kelis Was Here, the title of which was beginning to seem like an epitaph. But revivals don't come much fiercer or more joyful than the singer's new album, Flesh Tone, which enlists production from Will.I.Am and David Guetta and is built to detonate like a bomb on the dance floor. "No one's doing party music anymore," she says. "Everything has become so pop and clean and pretty that it sucks. I want to see people sweat!" Known for chameleon-like transformations, Kelis is conjuring a look she calls "animalistic and tribal and warrioresque"—fitting for a woman who racked up some defining experiences in her time out of the spotlight, including the birth of her child, divorce from her rapper husband, Nas, and a stint at the Cordon Bleu culinary school in Los Angeles (her specialty? Sauces, of course). "I needed to mix things up and make a fresh start," she says. "This record is like a deep breath. My lungs are filled again, and with that there's life."—A.L.

"I'm a loud person," says 21-year-old Hayley Williams, Paramore's fiery-haired, Lilliputian front woman, whose vocal adrenaline has made the band's ferocious pop punk more than just a teenage phenomenon. The band's 2009 album, Brand New Eyes, debuted at No. 2 on the Billboard chart, delivering the kind of angst-filled rock that makes you want to crank up the volume and curse every loser who's ever wronged you. Williams found inspiration from Paramore's own internal drama: In the midst of its sold-out European tour in 2008, the group canceled several dates. Williams, who dated Paramore guitarist Josh Farro (they broke up prior to the tour), says she and the boys needed some time apart. "I felt a little overprotected," she admits. "But now I can take care of myself." Besides, the Tennessean, who grew up adoring the Distillers' Brody Dalle and prefers a uniform of jeans and Nikes, has never been much of a girly girl. "[Onstage], my everyday thing would be a cut-up T-shirt and a good pair of pants that don't show booty cleavage when you headbang."—J.V.

Photographed March 16, 2010 in her suite at Le Parc Hotel in West Hollywood

"When I was eight, my mom showed me a picture of David Bowie. I said, `I want to look like that.' "

Twenty-two-year-old Elly Jackson, front woman of British electro duo La Roux (with publicity-shy partner Ben Langmaid), packs a uniquely keening wail that lavishes melancholy over the top of chirpy '80s-flashback dance beats, endowing them with an unlikely emotional heft. She's also a top-to-bottom pop star in the androgynous Bowie mold, from her hair—a flame-colored pompadour that constitutes the most image-defining (and gravity-defying) do since Amy Winehouse's beehive—to her mix 'n' match collision of aggressively shouldered zebra-print jackets and multicolored Mondrian-style tights. "I've always believed in presenting the whole package," Jackson says. "The way you look is such a massive part of who you are as an artist." Since the release of their self-titled 2009 debut album, La Roux has scored a slew of devastatingly addictive hits (including the disco-inflected breakup anthem "Bulletproof," an "I Will Survive" for the Facebook generation). Indeed, their fans are so enamored that they often turn up to concerts dressed like Jackson. "I get a lot of bras and pants thrown onstage," she says with a laugh. "Evidently, my androgyny appeals to both sexes."—A.L.

"I look at fashion like a Pollock painting. I love to mix and match styles together."

Twenty-six-year-old VV Brown (born Vanessa) got her nickname while attending a posh prep school in Northampton, England. "I used to be intrigued by hip-hop—De La Soul, Run-DMC, J Dilla—we'd have hip-hop battles in the playground," she says. "VV was my battle name." So it makes sense that after relocating to Los Angeles at just 18 to make a less-than-stellar debut album, VV moved back to London to do what she knew best: battle. "I was so stubborn," she says of signing her current deal. "I was like, `I don't care how many records I sell. I don't want you to fly me to New York to work with that guy who's got a new hit. I just want a record that's me.' " Which turned into this year's Travelling Like the Light, a peppy throwback filled with lush indie soul-pop, surf guitar trills, and doo-wop melodies, no doubt helping her earn a spot on Pink's UK summer tour. And though she exudes sweet rockabilly charm, you heard it here first—an invitation to the ultimate MC rabble-rouser: "I'm really good," she says; "I could totally battle against Kanye."—J.V.